Egg carton setup equipment



J y 15, 1 M. BURGER 2,843,026

EGG CARTON SETUP EQUIPMENT\ Filed July 27, 1954 2 Sheets-Sheet 1 IN V EN TOR.

July 15, 1958 M. BURGER EGG CARTON SETUP EQUIPMENT Filed July 27, 1954 2 Sheets-Sheet 2 INVENTOR.

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not; cAnroN sarnr EQUXPMENT Martin llurger, Morris, llL, assiguor, by mesne assignments, to Diamond Gardner Corporation, a corporation of Delaware Application July 27, 1954, Serial No. 446,679

7 Claims. (Cl. 93-37) The present invention relates to an improved device for erecting flexible paperboard egg cartons which, though illustrated as a manually operated unit, is equally well adapted to be embodied as a setup head in a high speed automatic carton erecting machine. Considered as an improvement in either class of equipment, the invention deals with the general sort of setup structure shown and described in the patents to Burger, Reissue No. 18,547, of July 26, 1932, and No. 2,668,482, of February 9, 1954.

It is an object of the invention to provide an improved setup head which is especially devised for the erection of a cellular paperboard carton of the heretofore so-called Troyk style, and as more particularly illustrated and described in a copending application of Richard F. Reifers, Serial No. 415,878, filed March 12, 1954, to which reference may be had to a detailed description of the improved carton features. Considered briefly, these features deal with a paperboard egg carton which, as distinguished from the Troyk style, is almost perfectly rectangular in section in a completed but flat, knocked-down condition, devoid of projecting, cell-forming partition elements at one or both ends thereof which are to be swung to and locked in upstanding relation to the carton walls and bottom, with the partitions paralleling one another.

The carton in question is freed from reliance upon such externally projecting partitions, and is thereby rendered a much more desirable one for reasons unnecessary to enlarge on here, by the employment of a split partition principle as a refinement of the characteristic Troyk carton features. In accordance with this principle ertain intermediate cross partitions, located between the ends of the carton, but inwardly next adjacent the endmost partitions in the illustrated form, are, in the fiat condition of the carton, derived from a single panel portion of a planar cross partition section, and are separated from one another by a transverse cut across the panel portion in question. They are, accordingly, swingable in opposite directions about longitudinally spaced hinges at the ends of said panel portion. the aforesaid endmost cross partitions to be hinged to the carton walls for outward swinging toward the carton ends, the material of these partitions being entirely within the end confines of the fiat knocked-down article, and of the paperboard blank from which it is made.

in setting up a flat carton of the foregoing general description to a compartmented or cellular, box-like condition, it is evident that a special arrangement of carton recting elements must be employed, capable of swinging the endmost partition elements in the fashion described, as well as manipulating the interiorly disposed elements, including the split partitions, in a predetermined, nonuniform fashion.

lt is therefore an object of the invention to provide an improved setup head for the erection of such a carton, either manually or automatically, and which will be characterized by the same degree of simplicity, ruggedness and reliability as the devices shown, described and claimed in the above entitled Burger patents. Further,

This in turn permits nited States Patent with minor changes the improved head is capable of erecting paperboard cartons of either the full dozen, nondivisible type, featuring two parallel rows of six cells, or of the divisible style, which is separable across a medial perforated or weakened line into two half sections of six cells each. Either of these adaptations involves in common the use of a special arrangement of swingable carton erecting elements or leaves coacting with fixed abutments, and each effects a simultaneous desired manipulation of full height partitions and split, partial height partitions to desired transversely extending and parallel relation to one another. A coordinately actuated longitudinal blade thereupon engages a bottom and longitudinal partition forming section of the carton and interlooks it with the thus positioned partitions.

Considered more specifically, it is an object of the invention to afford a carton setup head having two parallel series of fixed, transversely aligned and longitudinally spaced abutments with which swingable partition erecting leaves cooperate in the desired setup of the transverse or cross partitions. These elements include a pair adjacent each of the end extremities of the head which are mounted to swing outwardly of the latter, in the longitudinal direction, thereby swinging both sets of opposite, endmost partitions of the carton outwardly to the desired upstanding relation to the front and rear side carton walls. Further inwardly disposed erecting elements or leaves are simultaneously actuated to engage and swing the remaining cross partitions properly. These include sets of adjacent, oppositely swingable leaves, each of which rotates outwardly towards the respective opposite ends of the setup head, and toward fixed abutments on either side of the set. in so moving, these sets shift the partial height split cross partitions oppositely to parallel relation. Still other erecting leaves operate simultaneously on the re mainder of the full height cross partitions, swinging the same against a fixed abutment or abutments and in parallelism with all the other cross partitions. There may be some difference in the direction of swinging of the last named full height partitions depending by whether or not the carton is a divisible or non-divisible style, however, insofar as the principle of the present invention is concerned, this matter is immaterial. The improvement primarily resides in the scheme of and means for manipulating the endmost and split cell partitions, inasmuch as the former have a'different and improved arrangement than heretofore in relation to the ends of the body of the knocked-down carton, and the latter are defined and manipulated differently than heretofore in order to permit such arrangement.

The foregoing statements are indicative in a general way of the nature of the invention. Other and more specific objects will be apparent to those skilled in the art upon a full understanding of the construction and operation of the improved head.

A single embodiment of the invention is presented herein for purpose of illustration, but it will be appreciated that the invention may be incorporated in other modified forms coming equally within the scope of the appended claims.

In the drawings:

Fig. 1 is a top plan view of the improved setup device and its basic setup head, being partially broken away, the view showing the head in an open position of its erecting leaves for the reception and final setting up of a partially spread, box-like body;

Fig. 2 is a view, partially broken away, in longitudinal vertical cross section along line 22 of Fig. 1, further illustrating provisions for manipulating the partition erecting leaves and indicating in solid and dotted lines the operations performed by the head on a fragmentary carton portion; and

Fig. 3 is a fragmentary perspective view of a paperboard egg carton in setup, cellular condition, the boxlike outline of the carton body prior to erection being shown in dotted line.

A proper understanding of the structural arrangement and operation of the improved setup head only follows an understanding of the features of the carton which it is intended to erect, which is illustrated in Fig. 3. The carton, generally designated C, is characterized by generally parallel, upstanding front and rear wall panels a, b, respectively, and a bottom and longitudinal partition forming section 0 which is subdivided into two like halves by a medial longitudinally extending crease a. This crease constitutes the apex of a longitudinal partition portion of section 0 which is of inverted 4 Outline, viewed in Fig. 3, merging downwardly into upwardly convergent, bottom forming portions e.

A cross partition forming panel or section extends between the upper margins of the front and rear walls a, b,

to which it is integrally connected by triangular webs f of a well known sort. The cross partition section is made up of a plurality of cross partition elements g, h and i differing somewhat in outline and in relation to the orientation of their hinge connections in respect to the carton ends. divided by a longitudinally extending crease j, about which the partition section is folded on itself when the carton is in a fiat, knocked-down condition.

For simplicity of illustration, only a trifle more than one-half of the length of the carton C has been depicted in Fig. 3. This carton, as illustrated, is of a divisible style, being medially subdivided by a transversely extending perforated line k across its front and rear side walls and bottom and cross partition section. The carton is readily subdivided into two like sections by tearing along the thus weakened line. Being symmetric, in the longitudinal sense, about crease k, the carton is sufficiently illustrated in Fig. 3 for the purpose of this description.

In further and specific reference to the cross partition elements mentioned above, those designated g are disposed adjacent the ends of carton walls a, b and are hinged by the end webs f so as to swing outwardly about the latter and toward the ends, to the fully erected position shown in Fig. 3. This means that when the carton is in a fiat, knocked-down condition, end cross partition elements g will both lie in their entirety interiorly of the outer confines of the fiat article, rather than one or both thereof projecting substantially beyond the end margin, as characteristic of previous non-divisible and divisible style cartons of the so-called Troyk type.

A set of intermediate cross partitions h located inwardly adjacent partitions g are derived from material of the cross partition section or panel which is separated, between wall hinge webs f of partitions h, by a transverse slit or cut, this cut thus defining a lower margin 1 on each of the cross partitions 11. Accordingly, the latter are of only partial height, but sufiiciently tall to provide the desired egg protection between cells defined there between.

Finally, the cross partitions i are shown immediately adjacent either side of the weakening line of perforations k, being hinged by wall hinge webs f to swing toward one another into the parallel position shown when the carton is erected. Endmost cross partitions g and partitions i all have inturned hooks in adjacent the lower portion thereof, which hooks are lockingly engaged with apertures in bottom and longitudinal partition forming section 0 of the carton, while intermediate cross partitions it have similar but slightly smaller hooks n. These are correspondingly interlocked in inclined slots 0 of the inverted V-shaped section.

It is the function of the device, after carton C is first spread from fiat condition to a partially setup, boxlike outline, as indicated in dotted line in Fig. 3, to complete the erection of the same by swinging the cross partitions Each of these partitions is medially sub- W desired, on an automatic setup machine.

4 g, h, i to a parallel relation, extending transversely of walls a, b, and then to thrust bottom and longitudinal partition panel or section c into a V-shaped outline, in which the respective hooks m, n, are lockingly interengaged with the section.

Referring now to Figs. 1 and 2, the improved setup device, as illustrated in a manually operable adaptation, comprises an open, skeleton-like frame or bed 10, readily adapted with unimportant alterations for mounting, when This bed is preferably an integral casting, and it is practically identical to the bed of the setup device illustrated and described in Burger Patent 2,668,482, referred to above, as is also true of certain of the operating members associated with the bed. Hence reference may be made to that patent for further illustration and detailed descriptive matter.

Integral upstanding end brackets 11, 12 extend upwardly from bed 10, and an operating shaft 13 is appropriately journalled at its ends in bosses 14 of these brackets. A blade actuating boss 15 is fixedly secured on shaft 13 at the midpoint of the latter, which boss is castellated at one end to receive an offset extremity of a coil spring 16, the spring being anchored at its other end on left hand bracket boss 14. The spring biases member 15 in a direction to raise an integral blade supporting arm 17 thereof away from bed 10. An elongated bottom and partition deflecting blade 18 is loosely articulated to the arm 17 by means of a swivel connection, generally designated 19, and the blade is centered and guided in its upward and downward movements by a lug 20 at one end thereof, the lug moving in an upwardly opening slot 21 on the right hand bed bracket 11 in the operation of blade 18 in shaping the V-bottom and longitudinal partition section c.

Shaft 13 is rotatably actuated by a crank 22 secured on a cam member 23 fixed on the shaft externally of the right hand bed bracket. The cam member has a shaped surface cam configuration 24 about a portion of its periphery, which serves as an operating member for a rocker arm 25, and the partition erecting elements of the setup head are operated upon movement of this arm. It is in the arrangement of these elements in relation to one another and to certain fixed abutment elements on bed 10 that the improvement of the invention primarily resides, since the operating provisions described above are known, and are shown in Burger Patent 2,668,482 mentioned above.

Bed 10 has a pair of transversely spaced, parallel, longitudinally extending side plates 26, 27 integrally joined at their ends with brackets 11, 12, and each of these plates is provided with a series of longitudinally spaced, upwardly opening pivot slots 28, the slots of the respective plates being in transverse alignment with one another, so as to afford loose pivot bearings for the partition erecting leaves of the improved head.

Of these leaves, those designated 29 engage and erect the full-height, endmost cross partitions g of the carton; those designated 30, 31, constituting a set, engage and erect the partial height, split cell partitions h; while those designated 32 engage the remaining, full height cross partition i, depicted in Fig. 3 as immediately adjoining the longitudinal center of the carton, but not necessarily located in this particular location, as in a non-divisible style carton. Partition erecting leaves 29, 3t 31 and 32 are each pivotally mounted in the upwardly opening slots 28 by means of outwardly extending integral hinge pins 33 at the respective opposite sides of those elements, which affords a very inexpensive, readily assembled construction, yet one which has ample ruggedness for the intended purpose.

In order to assist in positioning the partially opened carton, as illustrated in dotted line in Fig. 3, on the setup head, prior to manpulation of the erecting leaves, the outermost and centermost leaves 29, 32 are provided with integral, horizontally projecting ledge elements 34,

on which the carton may be engaged tosteady the same.

with the upwardly tapered halves of longitudinally spaced leaves 29-32, inclusive, as illustrated in Fig. 1.

It is evident that, as shown in Fig. 2, certain of the partition erecting leaves will be required to have clockwise movement about their respective pivot pins 33 in swinging the carton cross partitions, while the remainder will have counterclockwise swinging movement. In the former group are the leaves 31 and 32 on the left of center abutment 31 and the leaves 30, 29 on the right side thereof While the-counterclockwise rotating leaves are the leaves 29, 30 to the left and the leaves 32, 31 to the right.

An improved operating linkage is provided to secure these motions, in the form of parallel elongated operating bars 37, 38 pivotally connected to integral depending extensions 39 on the respective leaves 29-32. Bar 37 extends along the longitudinal center line of the bed and is pivotally connected to extensions 39 of the clockwise acting leaves, as referred to above, while bar 38 is pivotally connected to the extensions of the remaining, counterclockwise acting leaves. Bar 37 has a pivotal connection 39' at its right hand end to an actuating rod 40 slidably guided through right hand bed bracket 11, and rod 40 engages an adjustable threaded tappet extension 41 on its far end. The extension 41 is held by operating arm 25, which is medially pivoted at 42 on a fork on bracket 11, and the opposite extremity of arm carries a follower roller 43 which rides along the outer surface of cam 24. Accordingly, rotation of crank 22 causes arm 25 to swing about its pivot, thrusting actuating rod inwardly and causing the partition erecting leaves whose extensions 39 are pivoted on the bar 37 to take desired clockwise rotation.

Opposite movement of the other parallel bar 38 is derived from a motion reversing linkage best shown in Fig. 1. It consists of a transverse rocker arm 45 medially pivoted at as on an inwardly disposed lug 47 on bed bracket 12. One end of arm 45 carries an anti-friction roller 43 which is engaged by a 'tappet or pusher block 49 on leaf-operating bar 37, while the opposite end of the arm has a further anti-friction roller 50 in engagement with a tappet member 51 on bar 38. It follows that swinging movement of arm 45 by bar 37 will cause opposite movement of bar 38, with resultant opposite, counterclockwise swinging movement of the desired partition erecting elements, namely elements 29, 30 on the left of the longitudinal center of the bed, as viewed in Fig. 2 and elements 32, 31 on the right hand side.

In the use of the improved setup head, a carton C, preliminarily opened to the box-like outline shown in dotted line in Fig. 3, is inverted and telescoped downwardly over the abutments 35 and setup leaves of the head, which preliminarily tilts the respective cross partition elements g, h, i from a coplanar position, in which they constitute one panel of the box-like outline, to the inclined position shown in solid line in Fig. 2. Horizontal edges of partitions g and 1' rest on ledges 34. Grasping the carton body firmly, the operator now swings crank 22 downwardly, whereupon cam 24 in engaging follower roller 23 on rocker arm 25 will rotate the latter, shifting rod 40'and leaf-actuating bar 37 to the left. Simultaneous reverse movement of actuating bar 38 is produced by the reversing rocker arm 45, with the result that the partition setup leaves 29, 30, 31, 32 swing toward positions illustrated in dotted lines in Fig. 2, and urge the partitions g, h and i to positions similarly shown.

As the leaves 29-32 swing in this fashion, the longi-- tudinal partition deflecting blade 18 swings downwardly, and at the time the leaves are finally positioned as described blade 18 engages medial longitudinal crease d of longitudinal partition section 0, forcing the same downwardly to its ultimate \l-shaped outline. Openings in section 0 receive the upwardly extending partition edges, and locking hooks in and n on the respective cross partitions g and h, as well as similar locking hooks on the remaining partitions i, are engaged in the locking apertures of inverted V-shaped longitudinal partition structure c, completing the erection of the carton. So completed the carton is firmly locked in the condition shown in Fig. 3 of the drawings, whereupon it is manually withdrawn from the setup head. In the case of an automatic setup machine this stripping operation is performed by appropriate mechanism.

The device is simple, compact, rugged and inexpensive, and is rapidly operated in a manual operation, not to mention its very high speed operation in an automatic setup procedure.

I claim:

1. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright position at an angle to the carton walls, comprising a setup head having a plurality of partition erecting elements movably mounted thereon in longitudinally spaced relation to one another, said elements comprising a pair of endmost elements at opposite ends of said head which are oppositely movable to shift'endmost cross partition elements towards said ends of the head to form the ends of said cartons, element abutment means on said head outwardly of each of said endmost elements to control the positioning of said endmost cross partition elements with relation to said carton walls, and an intermediate partition erecting element movably mounted on said head between said first named pair of elements to shift intermediate cross partitions, the setup head having mounted thereon a pair of oppositely moving parallel bars along the lengths of which the various oppositely moving elements are movably attached, and a motion reversing linkage connecting said bars whereby longitudinal movement in one direction imparted to one of said bars moves the elements attached thereto and simultaneously results in the respective movement of the other bar and the elements attached thereto in the opposite direction.

2. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright position at an angle to the carton walls, comprising a setup head having a plurality of partition erecting elements pivotally mounted thereon in longitudinally spaced rela tion to one another, said elements comprising a pair of endrnost elements at opposite ends of said head which are oppositely swingable about the pivots thereof to shift endmost cross partition elements towards said ends of the head to form the ends of said cartons, element abutment means on said head outwardly of each of said endmost elements to control the positioning of said endmost cross partition elements with relation to said carton walls, and intermediate partition erecting elements pivotally mounted on said head between said first named pair of elements to shift intermediate cross partitions said intermediate partition erecting elements including pairs oppositely swingable about the pivots thereof with relation to one another, the setup head having mounted thereon a pair of oppositely moving parallel bars along the lengths of which the various oppositely moving elements are pivotally secured, and a motion reversing linkage connecting said bars whereby longitudinal movement in one direction imparted to one of said bars pivots the elements secured thereto and simultaneously results in the respective longitudinal vandpivotal mm ement of the other.

bar and the elements attached thereto in the opposite direction.

3. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright position at an angle to the carton walls, comprising a setup head having a plurality of partition erecting elements movably mounted thereon in longitudinally spaced relation to one another, said elements comprising a pair of endmost elements at opposite ends of said head which are oppositely movable to shift endmost cross partition elements towards said ends of the head to form the ends f said cartons, element abutment means on said head outwardly of each of said endmost elements to control the positioning of said endmost cross partition elements with relation to said carton walls, and intermediate partition erecting elements movably mounted on said head between said first named pair of elements to move oppositely of and away from one another towards said opposite ends of said head, thereby to shift intermediate cross partitions, at least some of said elements juxtaposed with relation to one another prior to the movement thereof, the setup head having mounted thereon a pair of oppositely moving parallel bars along the lengths of which the various oppositely moving elements are pivotally secured, and a motion reversing linkage connecting said bars whereby longitudinal movement in one direction imparted to one of said bars pivots the elements secured thereto and simultaneously results in the respective longitudinal and pivotal movement of the other bar and the elements attached thereto in the opposite direction.

4. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright position at an angle to the carton walls, comprising a setup head having a plurality of partition erecting elements pivotally mounted thereon in longitudinally spaced relation to one another, said elements comprising a pair of endmost elements at opposite ends of said head which are oppositely s' rngable about the pivots thereof to shift endmost cross par -tion elements towards said ends of the head to form the ends of said cartons, element abutment means on said head outwardly of each of said endmost elements to control the positioning of said endrnost cross partition elements with relation to said carton walls, and intermediate partition erecting elements pivotally mounted on said head between said first named pair of elements, said intermediate partition erecting elements including at least one pair adapted to swing away from one another towards said opposite ends of said head, and adapted for juxtapositioning in a position of rest, said intermediate partition erecting elements further including single elements adapted to pivot oppositely of said endmost elements, all of said intermediate partition erecting elements thereby adapted to shift intermediate cross partitions, the setup head having mounted thereon a pair of oppositely moving parallel bars along the lengths of which the various oppositely moving elements are pivotally secured, and a motion reversing linkage connecting said bars whereby longitudinal movement in one direction imparted to one of said bars pivots the elements secured thereto and simultaneously results in the respective longitudinal and pivotal movement of the other bar and the elements attached thereto in the opposite direction.

5. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright position at an angle to the carton walls, comprising a setup head having a plurality of partition erecting elements pivotally mounted thereon in longitudinally spaced relation to one another, said elements comprising a pair of endmost elements at opposite ends of said head which are oppositely swingable about the pivots thereof to shift endmost cross partition elements towards said ends of the head, at least one pair of intermediate partition erecting elements pivotally mounted on said head between said first named pair of elements to swing away from one another towards said opposite ends of said head, thereby to shift intermediate cross partitions, and relatively fixed abutment members mounted in position to be engaged by said cross partitions as so moved by said respective erecting elements, one of said members positioned outwardly of each of said endmost elements to control the po tioning of said endmost cross partition elements with rtion to said carton walls, at least one of said members adapted to be engaged by a cross partition element on either side'thereof to control the positioning of the lastmentioned cross partition elements with relation to said carton wall, said last-mentioned abutment member intermediate of said outwardly positioned members, the setup head having mounted thereon a pair of oppositely moving parallel bars along the lengths of which the various oppositely moving elements are pivotally secured, and a motion reversing linkage connecting said bars whereby longitudinal movement in one direction imparted to one of said bar pivots the elements secured thereto and simultaneously results in the respective longitudinal and pivotal movement of the other bar and the elements attached thereto in the opposite direction.

6. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright posi tion at an angle to the carton walls, comprising a setup head having a plurality of partition erecting elements pivotally mounted thereon in longitudinally spaced relation to one another, said elements comprising a pair of endmost elements pivoted adjacent opposite ends of said head which are oppositely swingable about the pivots thereof to shift endmost cross partitions towards said ends of the head, and intermediate partition erecting elements disposed between said first named pair of elements, said intermediate elements being mounted on said head to swing oppositely of and away from one another towards said oposite ends of said head, thereby to shift said intermediate cross partitions, relatively fixed abutment members mounted in position to be engaged by said cross partitions as so moved by said respective erecting elements, one of said abutment members positioned outwardly of each of said endmost elements to control the positioning of said'endmost cross partition elements with relation to said carton walls, said intermediate partition erecting elements including at least one pair of partition erecting elements juxtaposed with relation to one another in a position of rest and adapted to pivot oppositely during the shifting of the intermediate cross partions associated therewith, an additional pair of intermediate partition erecting clements separated from one another by an abutment member adapted to limit the upright positioning of at least one cross partition, said additional pair of intermediate partition erecting elements adapted to swing towards one another and opposed sides of said last-mentioned abutment member, and operating means connected to said respective endmost and intermediate erecting elements to actuate the same simultaneously to erected position, said operating means comprising a pair of oppositely moving parallel bars along the lengths of which the various oppositely moving ele ments are pivotally secured, and a motion reversing linkage connecting said bars pivots the elements secured thereto and simultaneously results in the respective longitudinal and pivotal movement of the other bar and the elements attached thereto in the opposite direction.

7. Apparatus for erecting cellular paperboard cartons characterized by a plurality of hinged cross partitions adapted to be swung into parallelism and in upright position at an angle to the carton walls, and by a longitudinal partition section adapted to be interengaged with said cross partitions, comprising a setup head having a plurality of partition erectingelements pivotally mounted thereon in longitudinally spaced relation to one another, said elements comprising a pair of endmost elements pivoted adjacent opposite ends of said head which are oppositely swingable about the pivots thereof to shift endmost cross partitions towards said longitudinal partition section and said ends of the head, and at least one pair of intermediate partition erecting elements disposed between said first named pair of elements, said intermediate elements being mounted on said head to swing oppositely of and away from one another towards said partition forming section and towards opposite ends of said head, thereby to shift said intermediate cross partitions, relatively fixed abutment members mounted in position to be engaged by said cross partitions as so moved by said respective erecting elements, one of said abutment members positioned outwardly of each of said endmost elements to control the positioning of said endmost cross partition elements with relation to said carton Walls, operating means connected to said respective endmost and intermediate erecting elements to actuate the same simultaneously to erected position, said operating means comprising a pair of oppositely moving parallel bars along the length of which the various oppositely moving elements are pivotally secured, and a motion reversing linkage connecting said bars whereby longitudinal movement in one direction imparted to one of said bars pivots the elements secured thereto and simul* taneously results in the respective longitudinal and pivotal movement of the other bar and the elements attached thereto in the opposite direction, a member to engage said longitudinal partition section with said cross partitions, and means to actuate said last named member coordinately with said operating means.

References Cited in the file of this patent UNITED STATES PATENTS 2,228,943 Bergstein Jan. 14, 1941 2,592,880 Ferraro Apr. 15, 1952 2,612,086 Houtman Sept. 30, 1952 2,635,512 Harker Apr. 21, 1953 2,668,482 Burger Feb. 9, 1954 

